What is Audi A7's MMI system and how does it work?

I've heard about MMI system in Audi A7, but I'm not entirely sure what it does and how it works. Can someone explain it to me?

The MMI system in Audi A7 is a multi-media interface that allows you to control several functions of your vehicle. It uses a central display screen and a rotary/push-button controller to access various features like navigation, radio, phone, and vehicle settings.

One thing you should know is that the MMI system can be controlled through voice command as well. This can be very handy while driving, as you won't have to take your eyes off the road.